std::map man page

std::map< _Key, _Tp, _Compare, _Alloc > — A standard container made up of (key,value) pairs, which can be retrieved based on a key, in logarithmic time.

Synopsis

Public Types

typedef _Alloc allocator_type

typedef _Rep_type::const_iterator const_iterator

typedef _Alloc_traits::const_pointer const_pointer

typedef _Alloc_traits::const_reference const_reference

typedef _Rep_type::const_reverse_iterator const_reverse_iterator

typedef _Rep_type::difference_type difference_type

typedef _Rep_type::iterator iterator

typedef _Compare key_compare

typedef _Key key_type

typedef _Tp mapped_type

typedef _Alloc_traits::pointer pointer

typedef _Alloc_traits::reference reference

typedef _Rep_type::reverse_iterator reverse_iterator

typedef _Rep_type::size_type size_type

typedef std::pair< const _Key, _Tp > value_type

Public Member Functions

map () noexcept(is_nothrow_default_constructible< allocator_type >::value)
Default constructor creates no elements.
map (const _Compare &__comp, const allocator_type &__a=allocator_type())
Creates a map with no elements.
map (const map &__x)
Map copy constructor.
map (map &&__x) noexcept(is_nothrow_copy_constructible< _Compare >::value)
Map move constructor.
map (initializer_list< value_type > __l, const _Compare &__comp=_Compare(), const allocator_type &__a=allocator_type())
Builds a map from an initializer_list.
map (const allocator_type &__a)
Allocator-extended default constructor.
map (const map &__m, const allocator_type &__a)
Allocator-extended copy constructor.
map (map &&__m, const allocator_type &__a) noexcept(is_nothrow_copy_constructible< _Compare >::value &&_Alloc_traits::_S_always_equal())
Allocator-extended move constructor.
map (initializer_list< value_type > __l, const allocator_type &__a)
Allocator-extended initialier-list constructor.
template<typename _InputIterator > map (_InputIterator __first, _InputIterator __last, const allocator_type &__a)
Allocator-extended range constructor.
template<typename _InputIterator > map (_InputIterator __first, _InputIterator __last)
Builds a map from a range.
template<typename _InputIterator > map (_InputIterator __first, _InputIterator __last, const _Compare &__comp, const allocator_type &__a=allocator_type())
Builds a map from a range.
mapped_type & at (const key_type &__k)
Access to map data.
const mapped_type & at (const key_type &__k) const

iterator begin () noexcept

const_iterator begin () const noexcept

const_iterator cbegin () const noexcept

const_iterator cend () const noexcept

void clear () noexcept

const_reverse_iterator crbegin () const noexcept

const_reverse_iterator crend () const noexcept

template<typename... _Args> std::pair< iterator, bool > emplace (_Args &&... __args)
Attempts to build and insert a std::pair into the map.
template<typename... _Args> iterator emplace_hint (const_iterator __pos, _Args &&... __args)
Attempts to build and insert a std::pair into the map.
bool empty () const noexcept

iterator end () noexcept

const_iterator end () const noexcept

iterator erase (const_iterator __position)
Erases an element from a map.
_GLIBCXX_ABI_TAG_CXX11 iterator erase (iterator __position)

size_type erase (const key_type &__x)
Erases elements according to the provided key.
iterator erase (const_iterator __first, const_iterator __last)
Erases a [first,last) range of elements from a map.
allocator_type get_allocator () const noexcept
Get a copy of the memory allocation object.
std::pair< iterator, bool > insert (const value_type &__x)
Attempts to insert a std::pair into the map.
template<typename _Pair , typename = typename std::enable_if<std::is_constructible<value_type, _Pair&&>::value>::type> std::pair< iterator, bool > insert (_Pair &&__x)

void insert (std::initializer_list< value_type > __list)
Attempts to insert a list of std::pairs into the map.
iterator insert (const_iterator __position, const value_type &__x)
Attempts to insert a std::pair into the map.
template<typename _Pair , typename = typename std::enable_if<std::is_constructible<value_type, _Pair&&>::value>::type> iterator insert (const_iterator __position, _Pair &&__x)

template<typename _InputIterator > void insert (_InputIterator __first, _InputIterator __last)
Template function that attempts to insert a range of elements.
key_compare key_comp () const

size_type max_size () const noexcept

map & operator= (const map &__x)
Map assignment operator.
map & operator= (map &&)=default
Move assignment operator.
map & operator= (initializer_list< value_type > __l)
Map list assignment operator.
mapped_type & operator[] (const key_type &__k)
Subscript ( [] ) access to map data.
mapped_type & operator[] (key_type &&__k)

reverse_iterator rbegin () noexcept

const_reverse_iterator rbegin () const noexcept

reverse_iterator rend () noexcept

const_reverse_iterator rend () const noexcept

size_type size () const noexcept

void swap (map &__x) noexcept(/*conditional */)
Swaps data with another map.
value_compare value_comp () const
iterator find (const key_type &__x)
Tries to locate an element in a map.
template<typename _Kt > auto find (const _Kt &__x) -> decltype(_M_t._M_find_tr(__x))
Tries to locate an element in a map.
const_iterator find (const key_type &__x) const
Tries to locate an element in a map.
template<typename _Kt > auto find (const _Kt &__x) const -> decltype(_M_t._M_find_tr(__x))
Tries to locate an element in a map.
size_type count (const key_type &__x) const
Finds the number of elements with given key.
template<typename _Kt > auto count (const _Kt &__x) const -> decltype(_M_t._M_count_tr(__x))
Finds the number of elements with given key.
iterator lower_bound (const key_type &__x)
Finds the beginning of a subsequence matching given key.
template<typename _Kt > auto lower_bound (const _Kt &__x) -> decltype(_M_t._M_lower_bound_tr(__x))
Finds the beginning of a subsequence matching given key.
const_iterator lower_bound (const key_type &__x) const
Finds the beginning of a subsequence matching given key.
template<typename _Kt > auto lower_bound (const _Kt &__x) const -> decltype(_M_t._M_lower_bound_tr(__x))
Finds the beginning of a subsequence matching given key.
iterator upper_bound (const key_type &__x)
Finds the end of a subsequence matching given key.
template<typename _Kt > auto upper_bound (const _Kt &__x) -> decltype(_M_t._M_upper_bound_tr(__x))
Finds the end of a subsequence matching given key.
const_iterator upper_bound (const key_type &__x) const
Finds the end of a subsequence matching given key.
template<typename _Kt > auto upper_bound (const _Kt &__x) const -> decltype(_M_t._M_upper_bound_tr(__x))
Finds the end of a subsequence matching given key.
std::pair< iterator, iterator > equal_range (const key_type &__x)
Finds a subsequence matching given key.
template<typename _Kt > auto equal_range (const _Kt &__x) -> decltype(_M_t._M_equal_range_tr(__x))
Finds a subsequence matching given key.
std::pair< const_iterator, const_iterator > equal_range (const key_type &__x) const
Finds a subsequence matching given key.
template<typename _Kt > auto equal_range (const _Kt &__x) const -> decltype(_M_t._M_equal_range_tr(__x))
Finds a subsequence matching given key.

Friends

template<typename _K1 , typename _T1 , typename _C1 , typename _A1 > bool operator< (const map< _K1, _T1, _C1, _A1 > &, const map< _K1, _T1, _C1, _A1 > &)

template<typename _K1 , typename _T1 , typename _C1 , typename _A1 > bool operator== (const map< _K1, _T1, _C1, _A1 > &, const map< _K1, _T1, _C1, _A1 > &)

Detailed Description

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >>

class std::map< _Key, _Tp, _Compare, _Alloc >" A standard container made up of (key,value) pairs, which can be retrieved based on a key, in logarithmic time.

Template Parameters:

_Key Type of key objects.
_Tp Type of mapped objects.
_Compare Comparison function object type, defaults to less<_Key>.
_Alloc Allocator type, defaults to allocator<pair<const _Key, _Tp>.

Meets the requirements of a container, a reversible container, and an associative container (using unique keys). For a map<Key,T> the key_type is Key, the mapped_type is T, and the value_type is std::pair<const Key,T>.

Maps support bidirectional iterators.

The private tree data is declared exactly the same way for map and multimap; the distinction is made entirely in how the tree functions are called (*_unique versus *_equal, same as the standard).

Definition at line 96 of file stl_map.h.

Constructor & Destructor Documentation

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> std::map< _Key, _Tp, _Compare, _Alloc >::map () [inline], [noexcept]

Default constructor creates no elements.

Definition at line 162 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> std::map< _Key, _Tp, _Compare, _Alloc >::map (const _Compare & __comp, const allocator_type & __a = allocator_type()) [inline], [explicit]

Creates a map with no elements.

Parameters:

__comp A comparison object.
__a An allocator object.

Definition at line 174 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> std::map< _Key, _Tp, _Compare, _Alloc >::map (const map< _Key, _Tp, _Compare, _Alloc > & __x) [inline]

Map copy constructor.

Parameters:

__x A map of identical element and allocator types.

The newly-created map uses a copy of the allocation object used by __x.

Definition at line 185 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> std::map< _Key, _Tp, _Compare, _Alloc >::map (map< _Key, _Tp, _Compare, _Alloc > && __x) [inline], [noexcept]

Map move constructor.

Parameters:

__x A map of identical element and allocator types.

The newly-created map contains the exact contents of __x. The contents of __x are a valid, but unspecified map.

Definition at line 196 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> std::map< _Key, _Tp, _Compare, _Alloc >::map (initializer_list< value_type > __l, const _Compare & __comp = _Compare(), const allocator_type & __a = allocator_type()) [inline]

Builds a map from an initializer_list.

Parameters:

__l An initializer_list.
__comp A comparison object.
__a An allocator object.

Create a map consisting of copies of the elements in the initializer_list __l. This is linear in N if the range is already sorted, and NlogN otherwise (where N is __l.size()).

Definition at line 211 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> std::map< _Key, _Tp, _Compare, _Alloc >::map (const allocator_type & __a) [inline], [explicit]

Allocator-extended default constructor.

Definition at line 219 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> std::map< _Key, _Tp, _Compare, _Alloc >::map (const map< _Key, _Tp, _Compare, _Alloc > & __m, const allocator_type & __a) [inline]

Allocator-extended copy constructor.

Definition at line 223 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> std::map< _Key, _Tp, _Compare, _Alloc >::map (map< _Key, _Tp, _Compare, _Alloc > && __m, const allocator_type & __a) [inline], [noexcept]

Allocator-extended move constructor.

Definition at line 227 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> std::map< _Key, _Tp, _Compare, _Alloc >::map (initializer_list< value_type > __l, const allocator_type & __a) [inline]

Allocator-extended initialier-list constructor.

Definition at line 233 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> template<typename _InputIterator > std::map< _Key, _Tp, _Compare, _Alloc >::map (_InputIterator __first, _InputIterator __last, const allocator_type & __a) [inline]

Allocator-extended range constructor.

Definition at line 239 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> template<typename _InputIterator > std::map< _Key, _Tp, _Compare, _Alloc >::map (_InputIterator __first, _InputIterator __last) [inline]

Builds a map from a range.

Parameters:

__first An input iterator.
__last An input iterator.

Create a map consisting of copies of the elements from [__first,__last). This is linear in N if the range is already sorted, and NlogN otherwise (where N is distance(__first,__last)).

Definition at line 256 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> template<typename _InputIterator > std::map< _Key, _Tp, _Compare, _Alloc >::map (_InputIterator __first, _InputIterator __last, const _Compare & __comp, const allocator_type & __a = allocator_type()) [inline]

Builds a map from a range.

Parameters:

__first An input iterator.
__last An input iterator.
__comp A comparison functor.
__a An allocator object.

Create a map consisting of copies of the elements from [__first,__last). This is linear in N if the range is already sorted, and NlogN otherwise (where N is distance(__first,__last)).

Definition at line 273 of file stl_map.h.

Member Function Documentation

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> mapped_type& std::map< _Key, _Tp, _Compare, _Alloc >::at (const key_type & __k) [inline]

Access to map data.

Parameters:

__k The key for which data should be retrieved.

Returns:

A reference to the data whose key is equivalent to __k, if such a data is present in the map.

Exceptions:

std::out_of_range If no such data is present.

Definition at line 519 of file stl_map.h.

References std::map< _Key, _Tp, _Compare, _Alloc >::end(), std::map< _Key, _Tp, _Compare, _Alloc >::key_comp(), and std::map< _Key, _Tp, _Compare, _Alloc >::lower_bound().

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> iterator std::map< _Key, _Tp, _Compare, _Alloc >::begin () [inline], [noexcept]

Returns a read/write iterator that points to the first pair in the map. Iteration is done in ascending order according to the keys.

Definition at line 338 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> const_iterator std::map< _Key, _Tp, _Compare, _Alloc >::begin () const [inline], [noexcept]

Returns a read-only (constant) iterator that points to the first pair in the map. Iteration is done in ascending order according to the keys.

Definition at line 347 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> const_iterator std::map< _Key, _Tp, _Compare, _Alloc >::cbegin () const [inline], [noexcept]

Returns a read-only (constant) iterator that points to the first pair in the map. Iteration is done in ascending order according to the keys.

Definition at line 411 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> const_iterator std::map< _Key, _Tp, _Compare, _Alloc >::cend () const [inline], [noexcept]

Returns a read-only (constant) iterator that points one past the last pair in the map. Iteration is done in ascending order according to the keys.

Definition at line 420 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> void std::map< _Key, _Tp, _Compare, _Alloc >::clear () [inline], [noexcept]

Erases all elements in a map. Note that this function only erases the elements, and that if the elements themselves are pointers, the pointed-to memory is not touched in any way. Managing the pointer is the user's responsibility.

Definition at line 1043 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> size_type std::map< _Key, _Tp, _Compare, _Alloc >::count (const key_type & __x) const [inline]

Finds the number of elements with given key.

Parameters:

__x Key of (key, value) pairs to be located.

Returns:

Number of elements with specified key.

This function only makes sense for multimaps; for map the result will either be 0 (not present) or 1 (present).

Definition at line 1125 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> template<typename _Kt > auto std::map< _Key, _Tp, _Compare, _Alloc >::count (const _Kt & __x) const -> decltype(_M_t._M_count_tr(__x))

[inline]"

Finds the number of elements with given key.

Parameters:

__x Key of (key, value) pairs to be located.

Returns:

Number of elements with specified key.

This function only makes sense for multimaps; for map the result will either be 0 (not present) or 1 (present).

Definition at line 1131 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> const_reverse_iterator std::map< _Key, _Tp, _Compare, _Alloc >::crbegin () const [inline], [noexcept]

Returns a read-only (constant) reverse iterator that points to the last pair in the map. Iteration is done in descending order according to the keys.

Definition at line 429 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> const_reverse_iterator std::map< _Key, _Tp, _Compare, _Alloc >::crend () const [inline], [noexcept]

Returns a read-only (constant) reverse iterator that points to one before the first pair in the map. Iteration is done in descending order according to the keys.

Definition at line 438 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> template<typename... _Args> std::pair<iterator, bool> std::map< _Key, _Tp, _Compare, _Alloc >::emplace (_Args &&... __args) [inline]

Attempts to build and insert a std::pair into the map.

Parameters:

__args Arguments used to generate a new pair instance (see std::piecewise_contruct for passing arguments to each part of the pair constructor).

Returns:

A pair, of which the first element is an iterator that points to the possibly inserted pair, and the second is a bool that is true if the pair was actually inserted.

This function attempts to build and insert a (key, value) pair into the map. A map relies on unique keys and thus a pair is only inserted if its first element (the key) is not already present in the map.

Insertion requires logarithmic time.

Definition at line 558 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> template<typename... _Args> iterator std::map< _Key, _Tp, _Compare, _Alloc >::emplace_hint (const_iterator __pos, _Args &&... __args) [inline]

Attempts to build and insert a std::pair into the map.

Parameters:

__pos An iterator that serves as a hint as to where the pair should be inserted.
__args Arguments used to generate a new pair instance (see std::piecewise_contruct for passing arguments to each part of the pair constructor).

Returns:

An iterator that points to the element with key of the std::pair built from __args (may or may not be that std::pair).

This function is not concerned about whether the insertion took place, and thus does not return a boolean like the single-argument emplace() does. Note that the first parameter is only a hint and can potentially improve the performance of the insertion process. A bad hint would cause no gains in efficiency.

See https://gcc.gnu.org/onlinedocs/libstdc+… for more on hinting.

Insertion requires logarithmic time (if the hint is not taken).

Definition at line 588 of file stl_map.h.

References std::map< _Key, _Tp, _Compare, _Alloc >::end(), std::map< _Key, _Tp, _Compare, _Alloc >::key_comp(), std::map< _Key, _Tp, _Compare, _Alloc >::lower_bound(), and std::piecewise_construct.

Referenced by std::map< _Key, _Tp, _Compare, _Alloc >::insert().

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> bool std::map< _Key, _Tp, _Compare, _Alloc >::empty () const [inline], [noexcept]

Returns true if the map is empty. (Thus begin() would equal end().)

Definition at line 447 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> iterator std::map< _Key, _Tp, _Compare, _Alloc >::end () [inline], [noexcept]

Returns a read/write iterator that points one past the last pair in the map. Iteration is done in ascending order according to the keys.

Definition at line 356 of file stl_map.h.

Referenced by std::map< _Key, _Tp, _Compare, _Alloc >::at(), std::map< _Key, _Tp, _Compare, _Alloc >::emplace_hint(), and std::map< _Key, _Tp, _Compare, _Alloc >::insert().

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> const_iterator std::map< _Key, _Tp, _Compare, _Alloc >::end () const [inline], [noexcept]

Returns a read-only (constant) iterator that points one past the last pair in the map. Iteration is done in ascending order according to the keys.

Definition at line 365 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> std::pair<iterator, iterator> std::map< _Key, _Tp, _Compare, _Alloc >::equal_range (const key_type & __x) [inline]

Finds a subsequence matching given key.

Parameters:

__x Key of (key, value) pairs to be located.

Returns:

Pair of iterators that possibly points to the subsequence matching given key.

This function is equivalent to

std::make_pair(c.lower_bound(val),
               c.upper_bound(val))

(but is faster than making the calls separately).

This function probably only makes sense for multimaps.

Definition at line 1243 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> template<typename _Kt > auto std::map< _Key, _Tp, _Compare, _Alloc >::equal_range (const _Kt & __x) -> decltype(_M_t._M_equal_range_tr(__x))

[inline]"

Finds a subsequence matching given key.

Parameters:

__x Key of (key, value) pairs to be located.

Returns:

Pair of iterators that possibly points to the subsequence matching given key.

This function is equivalent to

std::make_pair(c.lower_bound(val),
               c.upper_bound(val))

(but is faster than making the calls separately).

This function probably only makes sense for multimaps.

Definition at line 1249 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> std::pair<const_iterator, const_iterator> std::map< _Key, _Tp, _Compare, _Alloc >::equal_range (const key_type & __x) const [inline]

Finds a subsequence matching given key.

Parameters:

__x Key of (key, value) pairs to be located.

Returns:

Pair of read-only (constant) iterators that possibly points to the subsequence matching given key.

This function is equivalent to

std::make_pair(c.lower_bound(val),
               c.upper_bound(val))

(but is faster than making the calls separately).

This function probably only makes sense for multimaps.

Definition at line 1272 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> template<typename _Kt > auto std::map< _Key, _Tp, _Compare, _Alloc >::equal_range (const _Kt & __x) const -> decltype(_M_t._M_equal_range_tr(__x))

[inline]"

Finds a subsequence matching given key.

Parameters:

__x Key of (key, value) pairs to be located.

Returns:

Pair of read-only (constant) iterators that possibly points to the subsequence matching given key.

This function is equivalent to

std::make_pair(c.lower_bound(val),
               c.upper_bound(val))

(but is faster than making the calls separately).

This function probably only makes sense for multimaps.

Definition at line 1278 of file stl_map.h.

References std::operator==().

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> iterator std::map< _Key, _Tp, _Compare, _Alloc >::erase (const_iterator __position) [inline]

Erases an element from a map.

Parameters:

__position An iterator pointing to the element to be erased.

Returns:

An iterator pointing to the element immediately following position prior to the element being erased. If no such element exists, end() is returned.

This function erases an element, pointed to by the given iterator, from a map. Note that this function only erases the element, and that if the element is itself a pointer, the pointed-to memory is not touched in any way. Managing the pointer is the user's responsibility.

Definition at line 944 of file stl_map.h.

Referenced by std::map< _Key, _Tp, _Compare, _Alloc >::erase().

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> size_type std::map< _Key, _Tp, _Compare, _Alloc >::erase (const key_type & __x) [inline]

Erases elements according to the provided key.

Parameters:

__x Key of element to be erased.

Returns:

The number of elements erased.

This function erases all the elements located by the given key from a map. Note that this function only erases the element, and that if the element is itself a pointer, the pointed-to memory is not touched in any way. Managing the pointer is the user's responsibility.

Definition at line 980 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> iterator std::map< _Key, _Tp, _Compare, _Alloc >::erase (const_iterator __first, const_iterator __last) [inline]

Erases a [first,last) range of elements from a map.

Parameters:

__first Iterator pointing to the start of the range to be erased.
__last Iterator pointing to the end of the range to be erased.

Returns:

The iterator __last.

This function erases a sequence of elements from a map. Note that this function only erases the element, and that if the element is itself a pointer, the pointed-to memory is not touched in any way. Managing the pointer is the user's responsibility.

Definition at line 1000 of file stl_map.h.

References std::map< _Key, _Tp, _Compare, _Alloc >::erase().

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> iterator std::map< _Key, _Tp, _Compare, _Alloc >::find (const key_type & __x) [inline]

Tries to locate an element in a map.

Parameters:

__x Key of (key, value) pair to be located.

Returns:

Iterator pointing to sought-after element, or end() if not found.

This function takes a key and tries to locate the element with which the key matches. If successful the function returns an iterator pointing to the sought after pair. If unsuccessful it returns the past-the-end ( end() ) iterator.

Definition at line 1079 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> template<typename _Kt > auto std::map< _Key, _Tp, _Compare, _Alloc >::find (const _Kt & __x) -> decltype(_M_t._M_find_tr(__x))

[inline]"

Tries to locate an element in a map.

Parameters:

__x Key of (key, value) pair to be located.

Returns:

Iterator pointing to sought-after element, or end() if not found.

This function takes a key and tries to locate the element with which the key matches. If successful the function returns an iterator pointing to the sought after pair. If unsuccessful it returns the past-the-end ( end() ) iterator.

Definition at line 1085 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> const_iterator std::map< _Key, _Tp, _Compare, _Alloc >::find (const key_type & __x) const [inline]

Tries to locate an element in a map.

Parameters:

__x Key of (key, value) pair to be located.

Returns:

Read-only (constant) iterator pointing to sought-after element, or end() if not found.

This function takes a key and tries to locate the element with which the key matches. If successful the function returns a constant iterator pointing to the sought after pair. If unsuccessful it returns the past-the-end ( end() ) iterator.

Definition at line 1104 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> template<typename _Kt > auto std::map< _Key, _Tp, _Compare, _Alloc >::find (const _Kt & __x) const -> decltype(_M_t._M_find_tr(__x))

[inline]"

Tries to locate an element in a map.

Parameters:

__x Key of (key, value) pair to be located.

Returns:

Read-only (constant) iterator pointing to sought-after element, or end() if not found.

This function takes a key and tries to locate the element with which the key matches. If successful the function returns a constant iterator pointing to the sought after pair. If unsuccessful it returns the past-the-end ( end() ) iterator.

Definition at line 1110 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> allocator_type std::map< _Key, _Tp, _Compare, _Alloc >::get_allocator () const [inline], [noexcept]

Get a copy of the memory allocation object.

Definition at line 328 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> std::pair<iterator, bool> std::map< _Key, _Tp, _Compare, _Alloc >::insert (const value_type & __x) [inline]

Attempts to insert a std::pair into the map.

Parameters:

__x Pair to be inserted (see std::make_pair for easy creation of pairs).

Returns:

A pair, of which the first element is an iterator that points to the possibly inserted pair, and the second is a bool that is true if the pair was actually inserted.

This function attempts to insert a (key, value) pair into the map. A map relies on unique keys and thus a pair is only inserted if its first element (the key) is not already present in the map.

Insertion requires logarithmic time.

Definition at line 731 of file stl_map.h.

Referenced by std::map< _Key, _Tp, _Compare, _Alloc >::insert().

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> void std::map< _Key, _Tp, _Compare, _Alloc >::insert (std::initializer_list< value_type > __list) [inline]

Attempts to insert a list of std::pairs into the map.

Parameters:

__list A std::initializer_list<value_type> of pairs to be inserted.

Complexity similar to that of the range constructor.

Definition at line 752 of file stl_map.h.

References std::map< _Key, _Tp, _Compare, _Alloc >::insert().

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> iterator std::map< _Key, _Tp, _Compare, _Alloc >::insert (const_iterator __position, const value_type & __x) [inline]

Attempts to insert a std::pair into the map.

Parameters:

__position An iterator that serves as a hint as to where the pair should be inserted.
__x Pair to be inserted (see std::make_pair for easy creation of pairs).

Returns:

An iterator that points to the element with key of __x (may or may not be the pair passed in).

This function is not concerned about whether the insertion took place, and thus does not return a boolean like the single-argument insert() does. Note that the first parameter is only a hint and can potentially improve the performance of the insertion process. A bad hint would cause no gains in efficiency.

See https://gcc.gnu.org/onlinedocs/libstdc+… for more on hinting.

Insertion requires logarithmic time (if the hint is not taken).

Definition at line 781 of file stl_map.h.

References std::map< _Key, _Tp, _Compare, _Alloc >::insert().

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> template<typename _InputIterator > void std::map< _Key, _Tp, _Compare, _Alloc >::insert (_InputIterator __first, _InputIterator __last) [inline]

Template function that attempts to insert a range of elements.

Parameters:

__first Iterator pointing to the start of the range to be inserted.
__last Iterator pointing to the end of the range.

Complexity similar to that of the range constructor.

Definition at line 807 of file stl_map.h.

References std::map< _Key, _Tp, _Compare, _Alloc >::emplace_hint(), std::map< _Key, _Tp, _Compare, _Alloc >::end(), std::map< _Key, _Tp, _Compare, _Alloc >::key_comp(), std::map< _Key, _Tp, _Compare, _Alloc >::lower_bound(), and std::piecewise_construct.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> key_compare std::map< _Key, _Tp, _Compare, _Alloc >::key_comp () const [inline]

Returns the key comparison object out of which the map was constructed.

Definition at line 1052 of file stl_map.h.

Referenced by std::map< _Key, _Tp, _Compare, _Alloc >::at(), std::map< _Key, _Tp, _Compare, _Alloc >::emplace_hint(), and std::map< _Key, _Tp, _Compare, _Alloc >::insert().

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> iterator std::map< _Key, _Tp, _Compare, _Alloc >::lower_bound (const key_type & __x) [inline]

Finds the beginning of a subsequence matching given key.

Parameters:

__x Key of (key, value) pair to be located.

Returns:

Iterator pointing to first element equal to or greater than key, or end().

This function returns the first element of a subsequence of elements that matches the given key. If unsuccessful it returns an iterator pointing to the first element that has a greater value than given key or end() if no such element exists.

Definition at line 1149 of file stl_map.h.

Referenced by std::map< _Key, _Tp, _Compare, _Alloc >::at(), std::map< _Key, _Tp, _Compare, _Alloc >::emplace_hint(), and std::map< _Key, _Tp, _Compare, _Alloc >::insert().

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> template<typename _Kt > auto std::map< _Key, _Tp, _Compare, _Alloc >::lower_bound (const _Kt & __x) -> decltype(_M_t._M_lower_bound_tr(__x))

[inline]"

Finds the beginning of a subsequence matching given key.

Parameters:

__x Key of (key, value) pair to be located.

Returns:

Iterator pointing to first element equal to or greater than key, or end().

This function returns the first element of a subsequence of elements that matches the given key. If unsuccessful it returns an iterator pointing to the first element that has a greater value than given key or end() if no such element exists.

Definition at line 1155 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> const_iterator std::map< _Key, _Tp, _Compare, _Alloc >::lower_bound (const key_type & __x) const [inline]

Finds the beginning of a subsequence matching given key.

Parameters:

__x Key of (key, value) pair to be located.

Returns:

Read-only (constant) iterator pointing to first element equal to or greater than key, or end().

This function returns the first element of a subsequence of elements that matches the given key. If unsuccessful it returns an iterator pointing to the first element that has a greater value than given key or end() if no such element exists.

Definition at line 1174 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> template<typename _Kt > auto std::map< _Key, _Tp, _Compare, _Alloc >::lower_bound (const _Kt & __x) const -> decltype(_M_t._M_lower_bound_tr(__x))

[inline]"

Finds the beginning of a subsequence matching given key.

Parameters:

__x Key of (key, value) pair to be located.

Returns:

Read-only (constant) iterator pointing to first element equal to or greater than key, or end().

This function returns the first element of a subsequence of elements that matches the given key. If unsuccessful it returns an iterator pointing to the first element that has a greater value than given key or end() if no such element exists.

Definition at line 1180 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> size_type std::map< _Key, _Tp, _Compare, _Alloc >::max_size () const [inline], [noexcept]

Returns the maximum size of the map.

Definition at line 457 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> map& std::map< _Key, _Tp, _Compare, _Alloc >::operator= (const map< _Key, _Tp, _Compare, _Alloc > & __x) [inline]

Map assignment operator. The dtor only erases the elements, and note that if the elements themselves are pointers, the pointed-to memory is not touched in any way. Managing the pointer is the user's responsibility.

Parameters:

__x A map of identical element and allocator types.

All the elements of __x are copied, but unlike the copy constructor, the allocator object is not copied.

Definition at line 296 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> map& std::map< _Key, _Tp, _Compare, _Alloc >::operator= (map< _Key, _Tp, _Compare, _Alloc > &&) [default]

Move assignment operator.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> map& std::map< _Key, _Tp, _Compare, _Alloc >::operator= (initializer_list< value_type > __l) [inline]

Map list assignment operator.

Parameters:

__l An initializer_list.

This function fills a map with copies of the elements in the initializer list __l.

Note that the assignment completely changes the map and that the resulting map's size is the same as the number of elements assigned. Old data may be lost.

Definition at line 319 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> mapped_type& std::map< _Key, _Tp, _Compare, _Alloc >::operator[] (const key_type & __k) [inline]

Subscript ( [] ) access to map data.

Parameters:

__k The key for which data should be retrieved.

Returns:

A reference to the data of the (key,data) pair.

Allows for easy lookup with the subscript ( [] ) operator. Returns data associated with the key specified in subscript. If the key does not exist, a pair with that key is created using default values, which is then returned.

Lookup requires logarithmic time.

Definition at line 474 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> reverse_iterator std::map< _Key, _Tp, _Compare, _Alloc >::rbegin () [inline], [noexcept]

Returns a read/write reverse iterator that points to the last pair in the map. Iteration is done in descending order according to the keys.

Definition at line 374 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> const_reverse_iterator std::map< _Key, _Tp, _Compare, _Alloc >::rbegin () const [inline], [noexcept]

Returns a read-only (constant) reverse iterator that points to the last pair in the map. Iteration is done in descending order according to the keys.

Definition at line 383 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> reverse_iterator std::map< _Key, _Tp, _Compare, _Alloc >::rend () [inline], [noexcept]

Returns a read/write reverse iterator that points to one before the first pair in the map. Iteration is done in descending order according to the keys.

Definition at line 392 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> const_reverse_iterator std::map< _Key, _Tp, _Compare, _Alloc >::rend () const [inline], [noexcept]

Returns a read-only (constant) reverse iterator that points to one before the first pair in the map. Iteration is done in descending order according to the keys.

Definition at line 401 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> size_type std::map< _Key, _Tp, _Compare, _Alloc >::size () const [inline], [noexcept]

Returns the size of the map.

Definition at line 452 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> void std::map< _Key, _Tp, _Compare, _Alloc >::swap (map< _Key, _Tp, _Compare, _Alloc > & __x) [inline], [noexcept]

Swaps data with another map.

Parameters:

__x A map of the same element and allocator types.

This exchanges the elements between two maps in constant time. (It is only swapping a pointer, an integer, and an instance of the Compare type (which itself is often stateless and empty), so it should be quite fast.) Note that the global std::swap() function is specialized such that std::swap(m1,m2) will feed to this function.

Definition at line 1032 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> iterator std::map< _Key, _Tp, _Compare, _Alloc >::upper_bound (const key_type & __x) [inline]

Finds the end of a subsequence matching given key.

Parameters:

__x Key of (key, value) pair to be located.

Returns:

Iterator pointing to the first element greater than key, or end().

Definition at line 1194 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> template<typename _Kt > auto std::map< _Key, _Tp, _Compare, _Alloc >::upper_bound (const _Kt & __x) -> decltype(_M_t._M_upper_bound_tr(__x))

[inline]"

Finds the end of a subsequence matching given key.

Parameters:

__x Key of (key, value) pair to be located.

Returns:

Iterator pointing to the first element greater than key, or end().

Definition at line 1200 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> const_iterator std::map< _Key, _Tp, _Compare, _Alloc >::upper_bound (const key_type & __x) const [inline]

Finds the end of a subsequence matching given key.

Parameters:

__x Key of (key, value) pair to be located.

Returns:

Read-only (constant) iterator pointing to first iterator greater than key, or end().

Definition at line 1214 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> template<typename _Kt > auto std::map< _Key, _Tp, _Compare, _Alloc >::upper_bound (const _Kt & __x) const -> decltype(_M_t._M_upper_bound_tr(__x))

[inline]"

Finds the end of a subsequence matching given key.

Parameters:

__x Key of (key, value) pair to be located.

Returns:

Read-only (constant) iterator pointing to first iterator greater than key, or end().

Definition at line 1220 of file stl_map.h.

template<typename _Key, typename _Tp, typename _Compare = std::less<_Key>, typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >> value_compare std::map< _Key, _Tp, _Compare, _Alloc >::value_comp () const [inline]

Returns a value comparison object, built from the key comparison object out of which the map was constructed.

Definition at line 1060 of file stl_map.h.

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Fri Sep 16 2016 libstdc++